Light emitting diode package having anodized insulation layer and fabrication method therefor

ABSTRACT

An LED package having an anodized insulation layer which increases heat radiation effect to prolong the lifetime LEDs and maintains high luminance and high output, and a method therefor. The LED package includes an Al substrate having a reflecting region and a light source mounted on the substrate and connected to patterned electrodes. The package also includes an anodized insulation layer formed between the patterned electrodes and the substrate and a lens covering over the light source of the substrate. The Al substrate provides superior heat radiation effect of the LED, thereby significantly increasing the lifetime and light emission efficiency of the LED.

CLAIM OF PRIORITY

This application claims the benefit of Korean Patent Application No.2006-0031093 filed on Apr. 5, 2006, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a Light Emitting Diode (LED) package ofhigh luminance and high output, which uses an LED as a light source anda method therefor. More particularly, the present invention relates toan LED package, which has a light source mounted in a reflecting regionof an aluminum (Al) substrate that is anodized to have an insulationlayer, thereby increasing the heat radiation effect of the LED duringthe light emission operation, prolonging the lifetime of the LED andmaintaining high luminance and output of the LED, and to a fabricationmethod therefor.

2. Description of the Related Art

In general, as shown in FIG. 1, a conventional LED package having an LEDas a light source includes an LED 215 mounted on a substrate 210 andelectrically connected to power to operate and emit light.

In such an LED package 200, the LED 215 generates light according to itscharacteristics and radiates heat at the same time. Thus, it is criticalthat the heat is discharged effectively to the outside to preventoverheating in order to maintain a long lifetime and good outputefficiency.

The conventional LED package 200 includes an LED 215 mounted on acircuit substrate 210 having a fixed patterned electrode 205, and alsoincludes a reflecting member 220 having a roughly the same size as theexterior of the substrate 210 and a reflecting surface 222 formedtherein. The reflecting member 220 is integrally fixed to the upper partof the substrate 210 by an epoxy resin, etc.

In such a conventional LED package 200, a concave reflecting surface 222is formed in the reflecting member 220, and thus the light from the LED215 is reflected forward by the reflecting surface 222.

However, in the conventional LED package 200, the substrate 210 is notmade of a material with high heat conductivity, i.e., good heatradiation capacity, for example, aluminum (Al), and thus heat radiationis not effective during the light emission operation of the LED 215.

In addition, the conventional LED package 200 needs to have thereflecting member 220 fixed by a separate process, hindering asimplified manufacturing processes. Furthermore, the rather inaccurateprocess of integrating the reflecting member 220 with the substrate canbe a major cause of defective products, thereby increasing the assemblycosts.

SUMMARY OF THE INVENTION

The present invention has been made to solve the foregoing problems ofthe prior art and therefore an aspect of the present invention is toprovide an LED package having an anodized insulation layer, which has asuperior heat radiation effect of an LED through a substrate, therebyincreasing the lifetime and light emission efficiency of the LED, and afabrication method therefor.

Another aspect of the invention is to provide an LED package which doesnot require a separate bonding process of a reflecting member to asubstrate and facilitates the process of aligning a lens to thesubstrate, thereby reducing the manufacturing costs through a simplifiedmanufacturing process, and a fabrication method therefor.

According to an aspect of the invention, the invention provides an LEDpackage which includes: an Al substrate having a reflecting region; alight source mounted on the substrate and electrically connected topatterned electrodes of the substrate, the light source comprising anLED; an anodized insulation layer formed between the patternedelectrodes and the substrate; a lens disposed over the light source ofthe substrate; and an Al heat radiator formed under the LED so as toenhance heat radiation capacity.

Preferably, the substrate has the light source disposed in thereflecting region thereof, the LED of the light source comprising blue,red and green LEDs to emit white light.

Preferably, the substrate has electrode connecting grooves adjacent tothe reflecting region thereof, the electrode connecting grooveselectrically connecting the light source to patterned electrodes withwires.

Preferably, the substrate has lens assembly grooves formed adjacent tothe reflecting region thereof, the lens assembly grooves defining thelocation of the lens part, and wherein the lens has projections formedon outer surfaces thereof which are assembled into the lens assemblygrooves.

Preferably, the anodized insulation layer is formed in the electrodeconnecting grooves.

According to another aspect of the invention, the invention provides amethod for fabricating a light emitting diode package. The methodincludes: etching a surface of a substrate to form a reflecting region;anodizing the substrate to form an insulation layer; forming patternedelectrodes on the substrate; mounting a light source on the substrateand electrically connecting the light source to the patternedelectrodes; and assembling a lens onto the substrate.

Preferably, the step of etching a surface of a substrate includesforming electrode connecting grooves adjacent to the reflecting regionof the substrate to electrically connect the light source to thepatterned electrodes with wires, and forming lens assembly grooves fordefining the location of the lens part on the substrate.

Preferably, the method further includes dicing a mother substrate into aplurality of the individual substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is an exploded perspective view illustrating an LED packageaccording to the prior art;

FIG. 2 is an exploded perspective view illustrating an LED packagehaving an anodized insulation layer according to the present invention;

FIG. 3 is a plan view illustrating the LED package having an anodizedinsulation layer according to the present invention;

FIG. 4 is a perspective view of the exterior of a lens provided in theLED package having an anodized insulation layer according to the presentinvention;

FIG. 5 is a sectional view illustrating the LED package having ananodized insulation layer according to the present invention;

FIG. 6 is a perspective view illustrating the LED package having ananodized insulation layer according to the present invention beingseparated from a mother substrate;

FIG. 7 is a plan view illustrating an LED package having an anodizedinsulation layer according to another embodiment of the presentinvention;

FIG. 8 is a sectional view illustrating the LED package according toanother embodiment of the present invention cut along the A-A line ofFIG. 7;

FIG. 9 is a plan view illustrating an LED package having an anodizedinsulation layer according to further another embodiment of the presentinvention; and

FIG. 10 is a sectional view illustrating the LED package according tofurther another embodiment of the present invention cut along the lineB-B of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Exemplary embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

As shown in FIG. 2, an LED package 1 having an anodized insulation layerincludes a substrate 10 made of an Al material. The substrate 10 is madeof an Al material which is relatively low cost and easily manufactured.

The substrate 10 has a reflecting region 20 formed in a center thereof.The reflecting region 20 is a recessed groove formed by etching. Asshown in FIG. 3, the reflecting region 20 is composed of a planarcentral reflecting area 22 where the light source 30 is mounted asdescribed later, i.e., a die bonding reflecting area and an inclinedreflecting area 24, i.e., a reflecting surface surrounding the centralreflecting area 22.

In addition, electrode connecting grooves 52 connecting the electrodesof the LEDs of the light source 30 with wires 40 and lens assemblygrooves 54 defining the location of the lens 70 described later areformed adjacent to the inclined reflecting area 24 of the reflectingregion 20 of the substrate 10.

The electrode connecting grooves 52 and the lens assembly grooves 54 areformed in shapes recessed from the surface of the substrate 10 but donot have a depth as large as the inclined reflecting area 24 of thereflecting region 20. Preferably, the electrode connecting grooves 52have a depth somewhat larger than that of the lens assembly grooves 54.This structure facilitates the placement of the wires 40 in theelectrode connecting grooves 52.

Moreover, the electrode connecting grooves 52 and the lens assemblygrooves 54 are not limited in the number in which they are provided.

There can be provided one or two electrode connecting grooves 52depending on the type of LED constituting the light source 30, and also,there can be provided a plurality of electrode connecting grooves 52corresponding to the number of LEDs mounted on the substrate 10.

In addition, the lens assembly groove 54 can be any reference groovesfor easily assembling the lens 70, and is not limited in the numberprovided.

In addition, patterned electrodes 12 a and 12 b are formed on thesubstrate 10 to supply power to the light source 30. The patternedelectrodes 12 a and 12 b are formed on a location on an upper surface ofthe substrate 10 adjacent to the reflecting region 20 and on an opposedlocation on a lower surface of the substrate 10, respectively. Thepatterned electrodes 12 a formed on an upper surface of the substrate 10are for electric connection of the LED constituting the light source 30,whereas the patterned electrodes 12 b formed on a lower surface of thesubstrate 10 serve as an electric connection pad of the LED packagemounted on a surface of another substrate (not shown) as a SurfaceMounted Device (SMD).

In addition, the patterned electrodes 12 a and 12 b are electricallyconnected to each other through a plurality of vias 16 penetrating thesubstrate 10.

The LED package 1 having an anodized insulation layer according to thepresent invention includes the light source 30 mounted on the substrate10 with an LED electrically connected to the patterned electrodes 12 aand 12 b, and anodized insulation layers 35 formed between the patternedelectrodes 12 a and the substrate 10 and between the patternedelectrodes 12 b and the substrate 10.

The anodized insulation layer 35 is for insulating the patternedelectrodes 12 a and 12 b from the substrate 10, and is formed by locallyor partially treating the substrate with Al₂O₃ through anodizing oranodic-oxidization.

Such an anodized insulation layer 35 has somewhat low heat conductivitybut has an excellent insulation capacity. It is formed between thepatterned electrodes 12 a and 12 b and the substrate 10 to supply thepower necessary for light emission operation of the light source 30.

In the meantime, such an anodized insulation layer 35 is formed in theelectrode connecting grooves 52 to be electrically insulated from thesubstrate 10, but is not formed in the reflecting region 20 of thesubstrate 10 so as not to hinder the reflection of the light from thelight source 30 to the outside.

In addition, the LED package 1 having an anodized insulation layer 35includes a lens 70 covering over the light source 30 of the substrate10. The lens 70 has a sectional shape with an upper hemispheric shape.As shown in FIG. 4, the lens 70 has projections 72 formed on outersurfaces thereof, which can be inserted into the lens assembly grooves54.

These projections 72 correspond to the lens assembly grooves 54. Suchprojections 72 and the lens assembly grooves 54 allow an operator toeasily find the mounting location or a referential location on thesubstrate 10 for attaching the lens 70. The lens 70 is adhered to thesubstrate 10 by a transparent adhesive resin.

The lens 70 adhered to the substrate 10 as described above is notdisposed on the electrode connecting grooves 52 of the substrate 10, asshown in FIG. 5. With the lens 70 not disposed on the electrodeconnecting grooves 52 as just described, the wires 40 can be placed inthe electrode connecting grooves 52 and the lens 70 does not hinder theplacement of the wires 40.

A fabrication method of the LED package 1 having an anodized insulationlayer according to the present invention entails the following steps.

The method of fabricating the LED package 1 having an anodizedinsulation layer according to the present invention starts with etchingan outer surface of the substrate 10 to form a reflecting region 20.

The reflecting region 20 includes a central reflecting area 22 where thelight source 30 is mounted and an inclined reflecting area 24surrounding the central reflecting area 22. The step of forming areflecting region 20 includes forming electrode connecting grooves 52connecting the electrode of the LED with wires 40, and lens assemblygrooves 54 allowing convenient setting of the location of the lens 70and easy fixing of the lens 70, adjacent to the inclined reflecting area24 of the reflecting region 20.

Both of these electrode connecting grooves 52 and the lens assemblygrooves 54 can be formed by etching.

Next, the substrate 10 is anodized to form insulation layer 35. In thiscase, the substrate 10 is anodized on surfaces thereof except on thesurface of the reflecting region 20 to form the insulation layers 35 ofAl₂O₃ on upper and lower surfaces of the substrate 10.

In particular, the insulation layers 35 are formed in the electrodeconnecting grooves 52 and the lens assembly grooves 54 so as to ensureelectric connection between the patterned electrodes 12 a and 12 b withthe light source 30.

Then, the patterned electrodes 12 a and 12 b are formed on the substrate10. The electrodes 12 a and 12 b are patterned on the substrate 10 inaccordance with the type of LED constituting the light source 30,whether it is a horizontal type where the LED has both electrodesconnected to the wires 40 from an upper surface thereof or whether it isa vertical type where the LED has an upper electrode connected to thewire from an upper surface thereof and a lower electrode placed at theunderside thereof.

After forming the patterned electrodes 12 a and 12 b as described above,the light source 30 is mounted on the substrate 10 and electricallyconnected to the patterned electrodes 12 a and 12 b.

This step is to establish electric connection via the wires 40.

After the electric connection of the light source 30 with the patternedelectrodes 12 a and 12 b, a lens 70 is assembled onto the substrate 10.In this step, a transparent adhesive resin is applied on the reflectingregion 20 of the substrate 10 and then the lens 70 is attached to thesubstrate 10.

In this step, the projections 72 formed on the outer circumferentialsurface of the lens 70 are aligned with the lens assembly grooves 54provided in the substrate 10, and the lens 70 is easily attached to thesubstrate 10 using an adhesive resin.

In the present invention, it is possible to fabricate each of thesubstrate 10 and the lens 70 separately, but alternatively as shown inFIG. 6, the substrates 10 can be diced from a large mother substrate 80.

That is, after a large mother substrate 80 is divided into a pluralityof substrates 10, the above steps are implemented on each of thesubstrates 10, and then a plurality of lenses 70 are respectivelyattached to the substrates 10. Then, the substrates 10 with the lenses70 are diced into individual LED packages 1 according to the presentinvention.

The process of using such a mother substrate 80 to produce a pluralityof LED packages 1 at once is well known in the art, and thus no furtherexplanation is provided.

In the LED package 1 having an anodized insulation layer fabricatedthrough the above described steps according to the present invention,the substrate 10 is made of an Al material. Such an Al substrate 10 hassuperior heat conductivity, allowing an excellent radiation effect ofheat generated during the light emission of the LED.

Moreover, as the reflecting region 20 is formed in the substrate 10 byetching, and the lens 70 is easily attached to the substrate 10, themanufacturing process is simplified to obtain a low cost LED package.

FIGS. 7 and 8 illustrate an LED package 1′ having an anodized insulationlayer according to another embodiment of the present invention.

The LED package 1′ employing an anodized insulation layer according tothe present invention, shown in FIG. 8, has a configuration andtechnical concept similar to those of the aforedescribed LED package 1with reference to FIGS. 2 to 6. Thus, the same reference numerals willbe used to designate the same components, with a prime next to each ofthe numbers.

The LED package 1′ employing an anodized insulation layer shown in FIGS.7 and 8 includes a plurality of LEDs, i.e., blue, red and green LEDs, asa light source 30′ to emit white light.

The LEDs are insulated by the anodized insulation layers 35′ andelectrically connected by wires 40′ to positive (+) or negative (−)electric terminals of the patterned electrodes 12 a′ and 12 b′.

In addition, the LED package 1′ also includes Al heat radiators 65′serving as heat slugs under the LEDs to allow superior heat radiationeffects. The Al heat radiators 65′ functioning as the heat slugs aresurrounded by the anodized insulation layer 35′ to form electricinsulation with other parts of the substrate 10′. Made of Al materialhaving superior heat conductivity, the Al heat radiators 65′ can achieveexcellent heat radiation effects.

Moreover, the LED package 1′ also has the insulation layers 35′ formedin the electrode connecting grooves 52′ and the lens assembly grooves54′ so as to ensure electric connection between the patterned electrodes12 a′ and 12 b′ and the light source 30′.

FIGS. 9 and 10 illustrate an LED package 1″ having an anodizedinsulation layer according to further another embodiment of the presentinvention.

This structure is similar to that of the LED package 1 with reference toFIGS. 2 to 6, and is based on the same technical concept. Thus, the samereference numerals are used to designate the same components, withdouble primes ″ next to each of the numbers.

The LED package 1″ having an anodized insulation layer according to thepresent invention, shown in FIGS. 9 and 10, includes a plurality ofLEDs, i.e., blue, red and green LEDs to emit white light. The LEDs areinsulated by the anodized insulation layers 35″ on the substrate 10″,and electrically connected by wires 40″ to positive or negative electricterminals of the patterned electrodes 12 a″ and 12 b″.

The LED package 1″ also includes Al heat radiators 65″ formed under theplurality of LEDs to obtain superior heat radiation effects. The Al heatradiators 65″ functioning as the heat slug parts are made of an Almaterial of superior heat conductivity, thereby achieving excellent heatradiation effects of the LEDs.

In addition, the LED package 1″ also has the insulation layer 35″ formedin the electrode connecting grooves 52″ and the lens assembly grooves54″ to ensure electric connection between the patterned electrodes 12 a″and 12 b″ with the light source 30″.

According to the present invention set forth above, a substrate is madeof an Al material to achieve superior heat radiation effect of LED,thereby increasing the lifetime and light emission efficiency of theLED.

Moreover, as a reflecting region is recessed in a substrate, there is noneed to bond a separate reflecting member as in the prior art, therebysimplifying the manufacturing process.

Furthermore, a lens has projections thereof assembled into lens assemblygrooves provided in the substrate, thereby easily determining themounting location of the lens. This enables an easy alignment of thelens with the substrate, thereby reducing the manufacturing costs.

While the present invention has been shown and described in connectionwith the exemplary embodiments, it will be apparent to those skilled inthe art that modifications and variations can be made without departingfrom the spirit and scope of the invention as defined by the appendedclaims.

1. A light emitting diode package comprising: an Al substrate having areflecting region; a light source mounted on the substrate andelectrically connected to patterned electrodes of the substrate, thelight source comprising a light emitting diode; an anodized insulationlayer formed between the patterned electrodes and the substrate; a lensdisposed over the light source of the substrate; an Al heat radiatorformed under the light emitting diode so as to enhance heat radiationcapacity; wherein the Al substrate is anodized on surfaces thereof toform the anodized insulation layers on upper and lower surfaces of thesubstrate, respectively, except on the surfaces of the reflecting regionso as not to hinder the reflection of the light from the light source tothe outside, and wherein the anodized insulation layer formed on thelower surface of the substrate surrounds the Al heat radiator to formelectric insulation with the Al substrate.
 2. The light emitting diodepackage according to claim 1, wherein the substrate has the light sourcedisposed in the reflecting region thereof, the light emitting diode ofthe light source comprising blue, red and green light emitting diodes toemit white light.
 3. The light emitting diode package according to claim1, wherein the substrate has electrode connecting grooves adjacent tothe reflecting region thereof, the electrode connecting grooveselectrically connecting the light source to the patterned electrodeswith wires.
 4. The light emitting diode package according to claim 1,wherein the substrate has lens assembly grooves formed adjacent to thereflecting region thereof, the lens assembly grooves defining thelocation of the lens part, and wherein the lens has projections formedon outer surfaces thereof which are assembled into the lens assemblygrooves.
 5. The light emitting diode package according to claim 3,wherein the anodized insulation layer is formed in the electrodeconnecting grooves.